Lech Walesa, leader of the outlawed Solidarity trade union, was summoned to appear before the Gdansk public prosecutor today in an apparent attempt to dissuade him from making a major public address on Thursday.

Walesa refused the summons, as well as another one calling him to the office of the Gdansk provincial governor. According to sources close to the 39-year-old Solidarity leader, the first summons was issued in connection with the alleged "dissemination of false information," a crime that carries a maximum sentence of five years in prison. The second summons apparently was for questioning about alleged financial irregularities in the management of the local Solidarity office.

Both moves constitute a threat against Walesa, who plans to make a speech on the 12th anniversary of the bloody suppression of food riots in Gdansk. In an advance text of the address released yesterday, Walesa urges Poles to use peaceful methods to struggle for the ideals of his outlawed Solidarity movement. Officials have said that any unofficial gathering in Gdansk will be illegal and broken up by police.

In a letter to the public prosecutor, made available to foreign correspondents here, Walesa said that his summons was invalid as it had not been drawn up correctly.

These preliminary legal formalities do not as yet constitute any specific criminal accusation against Walesa. But the fact that he has been summoned for questioning was interpreted by Western analysts here as psychological pressure by the martial-law government just as Walesa is getting ready to play a more active role on the political stage.

It seems unlikely at this point that the government really wants to send Walesa back to prison, as this would have the effect of turning him into a martyr in the eyes of millions of Solidarity supporters. But there are other methods by which they can prevent him from speaking, such as detaining him for up to 48 hours for questioning without bringing charges against him.

Thursday's anniversary is an emotional occasion for Walesa, who was a member of the strike committee at Gdansk's Lenin Shipyard in December 1970 when at least 55 workers were killed by security forces. It was this experience that later led him to demand the building of a monument to fallen workers outside the gates of the shipyard.

Walesa's letter to the prosecutor said that he received the summons at 12:30 p.m. today asking him to appear in person at 2 p.m. He complained that the summons was not signed and did not state precisely whether he was being summoned as a suspect.

The summons said that Walesa was wanted for questioning in connection with Article 271 of the penal code. This article, under the heading of "crimes against public order," covers the dissemination of "false information that can seriously harm the interests of the Polish People's Republic."

The article specifies that a person passing such information to "an institution which conducts activities against the political interests of Poland" can be sentenced to between six months and five years in jail.

Since a press conference following his return home on Nov. 14, Walesa has largely avoided meeting Western newsmen here. But he has released the texts of a letter to Poland's military leader, Gen. Wojciech Jaruzelski, and of the speech he intends to make.

In the planned speech, Walesa makes clear that he wants the gathering at the foot of the monument to disperse peacefully and does not plan to lead any kind of march through Gdansk.

The speech ends with the words: "I ask all of you . . . to go home in peace. Let no more damage be done . . . Let's not be pushed off peaceful methods of achieving our aims."

Polish newspapers today reported that an official investigation of the Solidarity chapter in Gdansk, which was headed by Walesa, has alleged that there were "many violations of financial regulations." The report said that Solidarity funds had been misused for such purposes as the publication of a book about Walesa and that many receipts were missing.

Walesa was summoned to the provincial finance office, apparently in connection with these allegations, on Tuesday. After refusing to attend, he received a second summons to appear at 10 a.m. Thursday.

The government has tried to depict Walesa, who became a symbol of the Solidarity movement between August 1980 and the military crackdown last December, as merely a private citizen.

The official press agency PAP reported today that Mariusz Wilk, former editor of the Solidarity weekly, and six others were arrested in Gdansk and Warsaw on suspicion of possessing and preparing illegal publications "containing false information likely to stir up public unrest."

In another development, Jaruzelski held talks today with the Soviet commander of the Warsaw Pact defense forces, Marshal Viktor Kulikov. Kulikov has been a frequent visitor to Poland during the past three years and is believed to have offered the Poles technical assistance for combating Solidarity.